I will leave this comment here as an example of using fear of death by a mystical being to ensure one's subscription to a particular religion. As if there wasn't already the fear of death before the mystical being's wrath was pronounced. One could have always argued, "You know...typically bad people live less fruitful lives than others and so by living in a bad way you will waste your preciously limited life." While that is not a very striking argument as it depends on one's definition of 'fruitful' and 'bad' and therefore bears little meaning, at least it does not resort to outright lies to ensure one's compliance with a moral code.
Ask yourself this - if lies are what help one build a moral code, how do you think the enforcing and reasoning of the code itself will proceed? Based on truth? I think not.